1. Field of the Invention
The present invention relates to an apparatus and method for converting an object display description document having functions of spatial synchronization and time synchronization and more particularly, to an apparatus and method for converting an object display description document in conformity with such a standard as MHEG (Multimedia and Hypermedia Expert Group)-5, DHTML (Dynamic Hyper Text Markup Language), and SMIL (Synchronized Multimedia Integration Language).
2. Description of the Prior Art
JPA 9-503088 entitled “APPARATUS AND METHOD FOR BROWSING INFORMATION” discloses a conventional system for optimizing data obtained at a viewer or browser for a document described with an object display description language.
As shown in FIG. 1, this reference exemplifies information browsing system 101 for browsing and organizing information from plural information sources 123. Knowledge base 109, which includes information source description 113, worldview 115 and system network view 117, is used for establishing a query plan including a sub plan. When the query sub plan is executed, the query plan is optimized by pruning redundant sub plans in accordance with information browsed by the executed sub plan. Graphical user interface 103 includes a hypertext browser integrated at a knowledge base browser/editor. Graphical user interface 103 allows a user to store an information source description in knowledge base 109 via a graphic operation and to browse information source descriptions previously stored. System 101 provides the use of query results that are constructed for avoiding of inquiring on constructed information sources and of concentrating queries from hypertext browsers on associated data sources that are not constructed. According to the above method, such an object is attained that information needless to inquire is fetched from the information source as seldom as possible.
With respect to an arrangement of sending optimized data from a server, JPA 10-171730 entitled “METHOD OF TRANSFERRING IMAGE” discloses an image transfer method capable of reducing the network load to transfer image data when a high resolution data is required at a client. As shown in FIG. 2, data received at the client is converted into an optimized high-resolution image using image conversion plug-in module 308. In this case, screen resolution setting program 306 is employed to check a resolution of a display device at the client. The result from program 306 is sent to image conversion program 304. The sent data becomes the most easy-to-view and high-qualified image at a browser watched from a reader. Although the optimization at the server side is considered in such a manner, all of servers do not send optimized data. Thus, users are required to display or store received data.
The above conventional technology has the following disadvantages.
A first disadvantage may be caused when the user selects necessary data with reference to its contents and obtains minimal necessary data while the minimal data contains data unnecessary to output or display for the user to the last. In such a case, the viewer or browser is loaded to work for analyzing and displaying the data unnecessary for showing the user. Therefore, a display output is delayed, and a data capacity is increased in case of storing data that also includes unnecessary data.
This is because the conventional viewer/browser has been developed to interpret the data sent from the server and make a display output. Therefore, thus configured viewer/browser analyzes all the obtained data and makes a display output even if all of the data are not required to be displayed because of introduced functions of spatial synchronization and time synchronization.
A second disadvantage is that although the server optimizes individual object data including an image as far as possible, the server does not perform optimization in consideration of a combination of data to be displayed. In this case, the data simply becomes a motion picture (object) group with a plurality of motion pictures (objects) but does not become substantially optimized data when images overlap with each other as the whole data.
This is because the server can superimpose the motion pictures and the like at the same time by the functions of spatial synchronization and time synchronization. In addition, when the server makes data to send, it sends the data with information, which indicates superimposition of the corresponding plural motion pictures, to the user.